2004 Swine Research Review

Animal Welfare

Pig-Moving Devices Tested for Effectiveness

Texas Tech University and Australian researchers teamed up to conduct four experiments with a goal of determining which hog-moving devices worked most efficiently and provided the best level of animal welfare.

When standing behind pigs, using a device to touch pigs on the back or ham was the most effective way to get pigs to move forward, researchers reported.

The sorting board was the most effective device for moving pigs. A paddle or electric prod were both equally effective at moving pigs forward; however, researchers subjectively ruled out the use of electric prods for moving pigs because of the inherent concerns over animal welfare.

The study was comprised of 320, 158-lb. to 198-lb. terminal Newsham Genetics barrows and gilts. One female worker moved pigs through a course using several moving devices. The devices were evaluated based on the time it took to move the pigs, and corresponding behavioral responses of the pigs.

The course included a holding pen, a staging area, pre-scale area and scale area (Figure 1). Pigs were moved three at a time from their home pens of 9-10 head. The floors in home pens, holding and staging areas were all concrete slotted. The aisle floor was solid concrete. The walls, staging and pre-scale areas were made of solid wood, painted white. The holding area had metal bar fencing, the same as the home pens.

In experiment 1, 160 pigs were moved through the course into the staging area using an electric prod or paddle. The prod caused about 15% of the pigs to occasionally jump. About two-thirds of the pigs moved forward when touched by either the prod or the paddle (Table 1).

Pigs were touched once firmly on the ham, neck, rear hock or back area with the electric prod or paddle. For both the prod and the paddle, the highest percentage of pigs moved forward when touched on the back, followed closely by being touched on the ham (Table 2). Only about 30% of the pigs moved forward when touched on their left or right side.

In experiment 2, 45 pigs were tested to assess the effect of paddle color on movement of pigs through the course. Red, blue and green paddles were tested. Paddle color did not alter the time it took to move the pigs.

Experiment 3 compared the time it took using the electric prod, sorting board and paddle to move pigs through the course (Figure 2). Ninety-nine pigs were moved, three at a time. Movement devices had a big impact on the time it took to move pigs. A handler using a board took less time to move pigs compared with an electric prod or paddle. The prod and paddle took equal time to move pigs through the course.

The incidence of pigs turning in the handling area, or vocalizing, in response to being moved, were also recorded (Table 3). Both are considered negative reactions to being handled.

Pigs turned more often in response to the paddle. The paddle was deemed the most effective when used in close quarters by rattling the device, but not physically touching the pig.

The number of vocalizations was greatest when either the prod or paddle was used to move pigs.

Experiment 4 compared the time it took to move pigs using the sorting board vs. the flag. Both were equal in time it took to move pigs. However, when the flag was waved, pigs appeared to be afraid of the moving device.